I'm interested in the pressure situation. I'm building a camper at the moment (door at the rear) and its been mentioned to me to put a vent on the roof. Does it have to face forwards to actually have wind driven in (my concern rain could also be driven in- don't say rain what's that") or can it be rear facing?


Out of interest on a panelvan I find that I get fumes in through the tailgate when I have the front window down, but not with all windows up? Almost seems opposite